Attenuation of Post-Meal Cardio-Metabolic Indices with Red Raspberries in Older Overweight/Obese Adults
Abstract Objectives Red raspberries (RRB) contain fiber and a unique combination of polyphenols with possible cardiovascular and metabolic benefits. The objective of this study was to evaluate the effects of acute red raspberry intake on cardio-metabolic markers of postprandial substrate metabolism and vascular endothelial function in older overweight/obese adults. Methods Thirty adults (age: 60 ± 4 years, BMI: 29.9 ± 3.0 kg m−2, mean ± SD) were randomized to the single-blinded, controlled, crossover trial. Participants consumed a high carbohydrate moderate fat breakfast (HCMF) meal containing 0 gram (control, 750 kcal) or 25 gram of freeze-dried RRB powder (2 cups fresh RRB equivalence, 752 kcal) on two occasions separated by 7 days washout period. Blood was collected at baseline and then again at 8 time points over 7.5 hours after test meals to determine glucose, insulin and triglyceride concentrations. Flow-mediated dilation (FMD) was assessed at baseline and then at 2 and 5 hours post test meal. Results A significant treatment * time interaction was observed for glucose (P = 0.014) and insulin (P < 0.01). Additionally, RRB significantly reduced the incremental area under the curve (iAUC) of insulin (P < 0.05), as well as the postprandial maximum concentration of glucose (P < 0.05), and insulin (P < 0.05). No significant treatment-related differences were observed for triglycerides. Vascular function as measured by changes in %FMD was significantly influenced by treatment (RRB 5.5 ± 0.3% versus control 4.7 ± 0.3%, P = 0.015). Conclusions Acute RRB supplementation attenuated postprandial glycemia and increased the vascular relaxation response after an HCMF meal challenge in a group of older overweight and obese individuals. Funding Sources This work was supported by the National Processed Raspberry Council.